Multichannel cannula and methods for using same

ABSTRACT

A method for delivering a substance to bone includes placing a stabilizing wire in a bone, creating a hole in the bone around the stabilizing wire, and providing a multichannel cannula. The multichannel cannula includes a first channel having an open proximal end and distal end, the first channel being configured to receive the stabilizing wire, and a second channel having an inlet portal and an exit portal that are in fluid communication. The cannula further includes a cap having a delivery port in fluid communication with the inlet portal and a channel for receiving the cannula therein, and a distal tip. The method further includes inserting the multichannel cannula into the hole in the bone such that the first channel receives the stabilizing wire, and delivering the substance into the bone by introducing the substance into the second channel such that the substance exits through the exit portal.

RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No. 13/679,312 filed Nov. 16, 2012 and entitled “Multichannel Cannula and Method for Using Same” which is hereby incorporated by reference in its entirety.

BACKGROUND

The present invention relates generally to the field of devices and methods for delivering substances to bone. More particularly, the present invention concerns devices and methods for delivering substances to the interior of fractured or otherwise injured bones, especially to the fracture interface. The present invention further relates to devices and methods for removing material from the interior of a bone.

As techniques for delivering substances to bone progress, there remains an imprecision during substance delivery prior to bone implant placement. A bone implant may be a bone screw, nail, or other device implanted into a bone to stabilize portions of a fractured bone. At least three techniques are currently available to deliver substances to bone. One technique involves delivering the substance into a drilled hole in a fractured bone without fracture stabilization. The lack of fracture stabilization causes difficulties in delivering substances to an intended location using this technique. A second technique includes drilling a separate hole in a bone for the substance to be delivered after implant placement. Drilling a separate hole causes additional trauma to the bone, and may also limit accessibility to the intended delivery location. In a third technique, the substance is delivered through the implant. This technique requires the use of a fenestrated or slotted implant.

SUMMARY

The embodiments described herein allow delivery of a substance (e.g., medication) to a fracture site after stabilization of the bone. Furthermore, the embodiments described herein allow delivery of a substance to bone through the same hole that will receive the bone implant, without requiring a separate hole to be drilled into the bone. The devices and methods described herein also allow material to be removed from the interior of a bone.

One embodiment of the invention relates to a method for delivering a substance to bone. The method includes placing a stabilizing wire in a bone and creating a hole in the bone around the stabilizing wire. A multichannel cannula is provided that includes a first channel having an open proximal end and an open distal end, the first channel being configured to receive the stabilizing wire. The multichannel cannula further includes a second channel having an inlet portal and an exit portal that are in fluid communication. The method further includes inserting the multichannel cannula into the hole in the bone such that the first channel receives the stabilizing wire, and delivering the substance into the bone by introducing the substance into the inlet portal of the second channel such that the substance exits the second channel through the exit portal.

Another embodiment of the invention relates to a method for removing material from a bone. The method includes placing a stabilizing wire in a bone and creating a hole in the bone around the stabilizing wire. A multichannel cannula is provided that includes a first channel having an open proximal end and an open distal end, the first channel being configured to receive a stabilizing wire. The multichannel cannula further includes a second channel having an inlet portal and an exit portal that are in fluid communication. The method further includes inserting the multichannel cannula into the hole in the bone such that the first channel receives the stabilizing wire. The method further includes coupling a suction device to the multichannel cannula, and removing a material from an interior of the bone by activating the suction device such that the material is drawn into the second channel through the exit portal of the second channel and the material exits the second channel through the inlet portal of the second channel.

Yet another embodiment of the invention relates to a multichannel cannula for delivering a substance to bone. The multichannel cannula includes a first channel having an open proximal end and an open distal end. The first channel is configured to receive a stabilizing wire. The multichannel cannula further includes a second channel having an inlet portal and an exit portal that are in fluid communication.

Alternative exemplary embodiments relate to other features and combinations of features as may be generally recited in the claims.

BRIEF DESCRIPTION OF THE FIGURES

The disclosure will become more fully understood from the following detailed description, taken in conjunction with the accompanying figures, wherein like reference numerals refer to like elements, in which:

FIG. 1 illustrates a bone with a stabilizing wire and a hole in the bone around the stabilizing wire, according to an exemplary embodiment.

FIGS. 2-5 illustrate cross-sectional views of various exemplary embodiments of a multichannel cannula.

FIG. 6 illustrates a multichannel cannula having a side port and a delivery portal, according to an exemplary embodiment.

FIG. 7 illustrates a multichannel cannula with a plurality of exit portals, including open distal ends of channels and multiple side ports, according to an exemplary embodiment.

FIG. 8 illustrates the bone and stabilizing wire shown in FIG. 1 with a multichannel cannula introduced over the stabilizing wire, according to an exemplary embodiment.

FIG. 9 illustrates a multichannel cannula with a stabilizing wire within a first channel and a delivery insert within a second channel.

FIG. 10 illustrates a cross-sectional view of an exemplary embodiment of a multichannel cannula.

FIG. 11 illustrates a longitudinal section view of an exemplary embodiment of a multichannel cannula with a distal tip and a cap.

FIG. 12 illustrates the multichannel cannula and cap shown in FIG. 11.

FIG. 13 illustrates the positioning of the cap along the multichannel cannula.

FIG. 14 illustrates the positioning of a plunger within a second channel of the multichannel cannula.

FIG. 15 illustrates a longitudinal section view of an exemplary embodiment of a multichannel cannula with a distal tip and a cap.

DETAILED DESCRIPTION

Before turning to the figures, which illustrate the exemplary embodiments in detail, it should be understood that the application is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology is for the purpose of description only and should not be regarded as limiting. For example, a femur is illustrated in the drawings, but the devices and methods described herein may be used in connection with any bone in the body, including but not limited to bones in the spine, arms, hands, legs, and feet.

Referring to FIG. 1, a bone 10 includes a fracture 2. The fracture 2 separates the bone into portions 10A and 10B. In surgical procedures to repair fractured bones, a stabilizing wire 4 may be used to hold bone portions together. The stabilizing wire 4 may be any type of wire used to temporarily or permanently secure portions of bone together, such as Kirschner wires or Steinmann pins. The stabilizing wire 4 is often placed in a fractured bone 10 prior to insertion of a more permanent bone implant, such as a bone screw, nail, or other fixation structure. In addition to stabilizing the bone portions 10A and 10B, the stabilizing wire 4 may serve as a guide for a drill or bone implant. For example, the bone 10 of FIG. 1 includes a hole 6 created to eventually receive a bone implant. To create the hole 6, a cannulated drill or reamer can be used to create a hole around the stabilizing wire 4 while the tip of the stabilizing wire 4 remains fixed in bone portion 10B. The hole 6 passes through the fracture 2. A bone implant to further secure bone portions 10A and 10B together can then be guided over stabilizing wire 4 and into the hole 6.

Referring to FIG. 8, according to an exemplary embodiment, a multichannel cannula 800 having two or more channels may be introduced over the stabilizing wire 4 to deliver substances to the interior of bone 10. In one embodiment, the multichannel cannula is introduced over the stabilizing wire 4 after creation of hole 6, but prior to placement of a bone implant into the hole 6. A first channel of the multichannel cannula receives the stabilizing wire 4. The other channels of the multichannel cannula may be used for delivering substances to the interior of bone 10, as described in more detail below. The substance delivered using the multichannel cannulas described herein may be any type of substance a user desires to deliver to the interior of a bone, including growth factors or medication such as calcium phosphate paste, an antibiotic, pain medication, or a chemotherapeutic agent.

The multichannel cannulas described herein are substantially elongated structures with two or more channels, as can be seen in FIGS. 6-8 and 11 (reference numbers 600, 700, 800, and 1100 respectively). The multichannel cannulas described herein include a first channel (e.g., 801 shown in FIG. 8). having an open proximal end (e.g., 824 shown in FIG. 8) and an open distal end (e.g., 822 shown in FIG. 8). The open proximal end and open distal end allow the first channel to be threaded over a stabilizing wire 4. Thus, the first channel is configured to receive a stabilizing wire 4. In one embodiment, the first channel is substantially cylindrical and has a diameter slightly larger than the diameter of the stabilizing wire. The side wall of the cylindrical first channel (as distinguished from the open ends of the first channel) may be continuous, meaning there are no open portals or other openings along the side wall of the first channel. In one embodiment, liquid cannot penetrate the side wall of the first channel.

The multichannel cannulas described herein further include a second channel (e.g., 802 shown in FIG. 8). The second channel includes at least one inlet portal (e.g., 820 shown in FIG. 8) and at least one exit portal (e.g., open distal end 810 shown in FIG. 8; side exit portals 708 shown in FIG. 7). In some methods described herein, the inlet portal of the second channel serves as an inlet for a substance to be delivered to the interior of a bone. In these embodiments, the exit portal of the second channel serves as an outlet for the substance. In other methods of using a multichannel cannula, the exit portal of the second channel serves as an inlet for material being drawn into the second channel and removed from the interior of a bone. In these embodiments, the inlet portal of the second channel serves out an outlet for this removed material. The inlet portal and exit portal of the second channel are thus in fluid communication to allow substances or materials to be delivered to or removed from the interior of a bone.

FIGS. 2-5 and 10 illustrate cross-sectional views of various embodiments of multichannel cannulas. The multichannel cannulas shown in FIGS. 2-5 each include at least two interior channels. The channels of a multichannel cannula may be structured in a variety of ways to enhance a user's ability to precisely deliver a substance to an intended location within a bone.

The multichannel cannula 200 shown in FIG. 2 includes a first channel 201 and a second channel 202. In this embodiment, first channel 201 is smaller than second channel 202, and first channel 201 is contained within the bounds of second channel 202. The cross-section of multichannel cannula 200 is substantially circular. In one embodiment, channel 201 receives a stabilizing wire 4 during a surgical procedure.

The multichannel cannula 300 shown in FIG. 3 also includes two channels—first channel 301 and second channel 302. In the embodiment of FIG. 3, first channel 301 and second channel 302 have substantially circular cross-sections and have approximately the same diameter. Furthermore, first channel 301 and second channel 302 are arranged next to each other such that the multichannel cannula 300 has a substantially ovular cross-section. During use of the multichannel cannula 300 of FIG. 3, either first channel 301 or second channel 302 may receive a stabilizing wire 4.

Referring to FIG. 4, multichannel cannula 400 includes a first channel 401, a second channel 402, and a third channel 403. The first channel 401 has a substantially circular cross-section, while second channel 402 and third channel 403 have crescent-shaped cross-sections. Second channel 402 and third channel 403 are arranged on either side of first channel 401 such that multichannel cannula 400 has a substantially ovular cross-section. In one embodiment, first channel 401 receives a stabilizing wire 4 during a surgical procedure.

Multichannel cannula 500, shown in FIG. 5, includes five separate channels. The cross-section of first channel 501 is substantially circular. Second channel 502, third channel 503, fourth channel 504, and fifth channel 505 have crescent-shaped cross-sections and are arranged around first channel 501. The cross-sectional shape of multichannel cannula 500 is thus an irregular shape, as illustrated in FIG. 5. In one embodiment, first channel 501 receives a stabilizing wire 4 during a surgical procedure.

Referring to FIG. 10, multichannel cannula 1000 includes two channels. In the embodiment of FIG. 10, first channel 1001 and second channel 1002 have substantially circular cross-sections. First channel 1001 has a smaller diameter than second channel 1002, and first channel 1001 is contained within the bounds of second channel 1002 and positioned such that first channel 1001 and second channel 1002 are coaxial. In one embodiment, channel 1001 receives a stabilizing wire 4 during a surgical procedure.

The multichannel cannulas described herein can be made of any material suitable for placement into a bone without harmful effects on the patient. In one embodiment, the multichannel cannula is made of stainless steel or other type of metal. In another embodiment, the multichannel cannula is made of a rigid plastic, such as polyethylketone, that cannot be easily bent or manipulated into alternative configurations. A rigid cannula may be advantageous to provide stability when introducing the cannula into a hole 6 in a bone 10. Furthermore, a rigid cannula provides stability for various procedures that a more flexible multichannel cannula may not provide. For example, if a surgeon desires to use a plunger or other device to push a substance from the multichannel cannula and into the bone, a rigid cannula may be more desirable. As another example, a rigid cannula is able to withstand more significant forces than a flexible cannula (e.g., forces applied to the cannula by a delivery device 628 or a suction device 826, and the forces resulting from movement of substances through the channels and through any open portals in the cannula).

FIG. 6 provides a perspective view of another embodiment of a multichannel cannula. Multichannel cannula 600 includes a first channel 601, a second channel 602, a delivery portal 604, and a side exit portal 608. The multichannel cannula 600 is threaded over a stabilizing wire 4, such as stabilizing wire 4 in bone 10 (as shown in FIG. 8). The stabilizing wire therefore lies within the first channel 601. The delivery portal 604 is coupled to an inlet portal 620 of the second channel 602 such that a substance can flow from the delivery portal 604, through the inlet portal 620, and into the second channel 602. The delivery portal 604 may be angled relative to the multichannel cannula 600, as shown in FIG. 6. In an alternative embodiment, the longitudinal axis of the delivery portal 604 is aligned parallel to the longitudinal axis of the multichannel cannula 600.

Various delivery devices can be coupled to the delivery portal 604 to assist in delivering substances to the second channel 602 of multichannel cannula 600. The delivery portal 604 may include a removable plug 606. In one embodiment, a user removes plug 606 to couple a delivery device 628 (illustrated schematically in FIG. 6) to delivery portal 604. The delivery device 628 may include a syringe, a pump, or a reservoir. Tubing 629 may be used to connect the delivery device 628 to the delivery portal 604. The type of delivery device selected by a user may depend on the type of substance to be delivered to the bone.

Once a substance has been delivered to second channel 602 of the multichannel cannula 600 through the inlet portal 620, the substance exits second channel 602 via a side exit portal 608 located on an outer wall of the second channel 602. In this embodiment, the distal end 610 of second channel 602 is closed, preventing the substance from exiting the distal end 610 of the second channel 602. However, in an alternative embodiment, the distal end 610 of the second channel 602 may be open to create an exit portal such that the substance can exit the second channel 602 through both the side exit portal 608 and the open distal end 610. During use of multichannel cannula 600, a user can align the side exit portal 608 with the area of the bone to be treated with the substance.

Referring to FIG. 7, multichannel cannula 700 includes five channels (701-705), each with an open distal end that can serve as an exit portal for substance delivery. In this embodiment, the fourth channel 704 includes a plurality of side exit portals 708, although any of the other channels 702-705 may include one or more side exit portals. The first channel 701 is configured to receive stabilizing wire 4 during a surgical procedure. A substance can be delivered to the inlet portals of any of channels 702-705 via a delivery portal, such as the delivery portal 604 described in connection with FIG. 6. In one embodiment, the substance is delivered to fourth channel 704. The substance then travels through fourth channel 704, exiting through side exit portals 708 and the exit portal created by the open distal end 710 of the fourth channel 704. In an alternative embodiment, the distal end 710 of fourth channel 704 is closed to prevent substance from exiting the distal end 710. The multiple exit portals 708, 710 in the embodiment of FIG. 7 allow the substance to be delivered to multiple areas within the interior of a bone. For example, the open distal end 710 may deliver the substance to a distal end of a hole 6 in a bone (e.g., in bone 10 shown in FIG. 8) while the exit portals 708 deliver the substance to one or more fracture sites 2.

FIG. 11 provides a cross-section view of another embodiment of a multichannel cannula. Multichannel cannula 1100 includes a first channel 1101, a second channel 1102, and side exit portals 1109. The multichannel cannula 1100 is threaded over a stabilizing wire 4, such as stabilizing wire 4 in bone 10 (as shown in FIG. 8). The stabilizing wire therefore lies within the first channel 1101. The distal end of cannula 1100 may include a distal tip 1103. As shown, the distal tip 1103 may include a tapered portion 1104 extending from the distal end of the cannula 1100. An engagement portion 1105 is coupled to the distal ends of the first channel 1101 and the second channel 1102. In the embodiment shown, the engagement portion may be configured to fit between the side wall of the first channel 1101 and the second channel 1102. The distal tip 1103 further includes a channel 1106 for receiving a portion of the stabilizing wire 4 therethrough.

As shown in FIGS. 11 and 12, multichannel cannula 1100 may also include a cap 1120. The cap 1120 has a housing portion with a channel for coupling to a portion of the proximal end of cannula 1100. The channel of the cap 1120 may extend from first end through a second end of the housing portion for receiving the stabilizing wire 4 therethrough. In a preferred embodiment, the cap 1120 is affixed to the multichannel cannula 1100, such as during production of the cannula 1100. In an alternative embodiment, the cap 1120 may be removable. The cap 1120 may be positioned at the site of the hole in the bone, such as hole 6 as shown in FIG. 8, in order to serve as a plug. In this way, cap 1120 plugs the hole 6 and may prevent irrigation or other substance being delivered to the site from coming back up through the hole 6 in the bone. In another embodiment, a separate temporary plug or seal may be added to the cannula to plug the hole 6 in the bone. In the embodiment shown, cap 1120 also has a delivery portal 1122. The delivery portal 1122 is coupled to an inlet portal of the second channel 1102 such that a substance can flow from the delivery portal 1122, through the inlet portal, and into the second channel 1102. As described in connection with FIG. 6, various delivery devices can be coupled to the delivery portal 1122 to assist in delivering substances to the second channel 1102 of multichannel cannula 1100. The delivery portal 1122 may include a removable plug 1123. The delivery device may include a syringe, a pump, or a reservoir. Tubing may be used to connect the delivery device to the delivery portal 1122.

Once a substance has been delivered to second channel 1102 of the multichannel cannula 1100 through the inlet portal, the substance exits second channel 1102 via a side exit portal 1109 located on an outer wall of the second channel 1102. During use of multichannel cannula 1100, a user can align the side exit portal 1109 with the area of the bone to be treated with the substance. In an alternative use, the desired location of the side portal 1109 can be determined at the time of the procedure, including after the stabilizing wire has been inserted and the hole in the bone has been created, to determine the preferred site of substance delivery. Thus, once the desired location is determined, the side portal 1109 can be created in the outer wall of the second channel 1102, or in another location on the multichannel cannula 1100 from which the substance can be delivered to the target site in the bone.

As shown in FIG. 13, an embodiment of the cap 1120 has a flange 1127 to provide improved gripping capability for positioning the cap 1120, if necessary. In some embodiments, the cap 1120 may be removed in order to accommodate the passage of a plunger 1130, such as the plunger 1130 shown in FIGS. 14 and 15. FIG. 14 depicts the plunger 1130 being used to assist with delivery of a substance through an exit portal, such as exit portal 1109. The plunger 1130 is configured to pass through the multichannel cannula 1100 in the second channel 1102 after a substance has been introduced into the channel 1102 through the inlet portal. As shown in FIG. 15, the cap 1120 and the plunger 1130 may be configured to engage such that a distal portion of the plunger 1130 is received in and engages with the channel of the cap 1120. In this embodiment, the cap 1120 may be affixed to the cannula 1100 or may be removable. The plunger 1130 fits around the first channel 1101 and may have a distal end configured to fit in the channel of the cap 1120 and capable of being moved within the second channel 1102 of the cannula 1100.

In an alternative embodiment, the second channel 1102 may have a distal opening into the first channel 1101. In this embodiment, the first channel 1101 may have a distal opening for the stabilizing wire 4 and a side opening 1109 for the substance to exit to the bone. The plunger 1130 in this embodiment would be configured to move within the first channel 1101, over the stabilizing wire 4, to deliver the remaining material to the desired area.

FIG. 8 illustrates a multichannel cannula 800 placed within bone 10 for substance delivery. The multichannel cannula 800 illustrated in FIG. 8 includes at least a first channel 801 and a second channel 802. First channel 801 is shown threaded over stabilizing wire 4. Second channel 802 is therefore used for substance delivery or to remove material from the interior of a bone. In the embodiment shown, the second channel 802 includes one or more expandable portions 830. The expandable portions 830 may be balloons configured to expand between the outside of the cannula 800 and the sidewall of the hole 6 formed in the bone. The expandable portions may provide stabilization to the cannula inserted in the bone and/or may provide a mechanism to isolate certain areas of the bone for delivery of the substance via the cannula 800. For example, a first expandable portion 830 may be positioned below an exit portal and another expandable portion 830 positioned above the exit portal, such that substance delivered through the exit portal is only delivered to the portion of the bone between the two expandable portions 830. In another example, the expandable portions 830 may provide temporary stabilization of the cannula when extended medication delivery is needed (such as several hours or days). In this way, medication may be delivered over an extended period of time prior to, as an example, placement of an implant. Any of the embodiments of multichannel cannulas described herein (e.g., 200, 300, 400, 500, 600, 700, 800, 900, 1000, and 1100), and any combination of the features of these embodiments, may be utilized in the manner shown in FIG. 8 to either deliver a substance to bone or remove material from the interior of a bone. Thus, references and disclosures related to methods for using multichannel cannula 800 are to be understood to be references and disclosures related to methods for using any of the other structural embodiments of multichannel cannulas described herein.

One method of delivering a substance to bone according to an exemplary embodiment includes placing stabilizing wire 4 into bone 10 and creating a hole 6 in the bone 10 around the stabilizing wire 4, as described above. The method further includes providing a multichannel cannula 800 having a first channel 801 with an open proximal end 824 and an open distal end 822. As also described above, the proximal end 824 and distal end 822 of the first channel 801 are open so that the first channel 801 can receive the stabilizing wire 4. The multichannel cannula 800 further includes a second channel 802 having an inlet portal 820 and an exit portal 818 that are in fluid communication.

The multichannel cannula 800 may be inserted into the hole 6 in the bone 10 such that the first channel 801 receives the stabilizing wire 4. During the step of inserting the multichannel cannula 800 into the hole 6, the multichannel cannula 800 can be inserted into the proximal end 6A of hole 6 to any desired depth. The expandable portions 830 may be inserted into the hole 6 in a deflated state. When the cannula 800 is in place, and the exit portal 818 is at the desired position, the expandable portions 830 may be inflated. The inflated expandable portions 830 may provide stabilization of the cannula 800 at the desired location. A substance is then delivered to the interior of bone 10 by introducing the substance into the inlet portal 820 of the second channel 802 such that the substance exits the second channel 802 through the exit portal 818 (i.e., the open distal end 810 of second channel 802). In one embodiment, the multichannel cannula 800 is inserted into hole 6 such that the distal end 809 of the multichannel cannula 800 is near fracture 2. The substance can therefore be delivered to the fracture site through the open distal end 810 of the second channel 802. In another embodiment, the multichannel cannula 800 is inserted farther into hole 6 such that substance is delivered through the open distal end 810 of the second channel 802 closer to the distal end 6B of hole 6. In an embodiment having side exit portals, such as the side exit portals 1109 in FIG. 11, the expandable portions 830 may also serve to isolate certain areas of the bone, such as the area near fracture 2, so that the delivered substance is focused at the desired area.

A user may select a multichannel cannula having a particular configuration and number of exit portals depending on a patient's bone fracture. For example, some types of fractures may be most easily treated by delivering a substance to a location that can be aligned with a distal end of a multichannel cannula. In this scenario, a user may select a multichannel cannula 800 in which the distal end 810 of a second channel 802 is open such that the substance can be delivered to bone 10 through this open distal end 810. In connection with other types of fractures, the user may desire to treat the bone 10 by delivering medication to one or more locations along the periphery of a hole 6 in the bone 10. Thus, a user may select a multichannel cannula 800 in which distal end 810 of second channel 802 is closed, and a substance is delivered to the bone through side exit portals such as those described in connection with FIGS. 6 and 7. In yet another embodiment, a substance may be delivered to bone 10 through a channel in multichannel cannula 800 having both an open distal end 810 and one or more side exit portals.

The multichannel cannula 800 may also be used during treatment of a patient with a weakened, but unfractured bone. A patient's bone can be weakened due to osteoporosis, metastasis of a cancer, or other disease that causes bone deterioration. A surgeon may be able to analyze the state of the patient's bone and determine areas that are likely to sustain a fracture in the future. To treat the weakened bone, a stabilizing pin 4 is inserted and a hole is drilled into the bone. The multichannel cannula 800 is then threaded over the stabilizing pin 4. A cement (e.g., calcium phosphate paste, methylmethacrylate) is injected through a channel of the multichannel cannula 800. The cement penetrates the surrounding bone and strengthens the area. After removal of the multichannel cannula 800, the hole in the bone may be filled with cement or a bone implant.

Prior to or during substance delivery, a user may rotate the multichannel cannula 800 around the stabilizing wire 4. Rotating the multichannel cannula 800 may help a user align an exit portal with an intended delivery location within the bone in order to direct substance delivery to the intended delivery location. Furthermore, the ability to rotate the multichannel cannula 800 around a stabilizing wire 4 may help during guidance of the multichannel cannula 800 proximally and distally within hole 6.

In addition to being useful for substance delivery to the bone, the multichannel cannula as described herein may be used in accurate positioning of implants made of absorbable materials and including reservoirs containing medications or other substances. The cannula may also be used for passage of debriding tools or imaging devices that are used during the surgical procedure.

Fluoroscopic guidance may increase a user's ability to precisely deliver a substance to a desired location within bone 10. The ability to view the multichannel cannula 800 during insertion allows a user to adjust the position of multichannel cannula 800 to precisely align any exit portals of the multichannel cannula 800 with the intended delivery sites within bone 10. Once the multichannel cannula 800 is positioned and substance delivery has begun, the user can use fluoroscopic guidance to determine whether any adjustments to the position of the multichannel cannula 800 should be made to more precisely deliver the substance. For example, based on fluoroscopic guidance, the user may determine that the multichannel cannula 800 should be inserted farther into hole 6. As another example, the image guidance may indicate that multichannel cannula 800 should be rotated about stabilizing wire 4 to increase delivery accuracy.

The multichannel cannulas described herein may include radiopaque markers to facilitate image guidance. The radiopaque markers may be located on or near the distal tip of the multichannel cannula. In one embodiment, separate radiopaque markers are provided near the distal opening of multiple channels of the multichannel cannula. Radiopaque markers may also be provided near side portal openings in the cannula. The radiopaque markers assist a user in accurately positioning the multichannel cannula during a surgical procedure to deliver or remove a substance from a bone. Furthermore, the markers allow a user to see where a substance is exiting or entering the multichannel cannula.

Referring to FIG. 9, a multichannel cannula 900 in accordance with another exemplary embodiment includes a first channel 901 and a second channel 902. The second channel 902 includes a side exit portal 908 for the substance to exit the second channel 902. In the embodiment of FIG. 9, an insert 912 having an exit portal 914 is used in combination with multichannel cannula 900 to deliver a substance to bone. In an alternative embodiment, the insert 912 includes multiple side exit portals (not shown). The insert 912 may be one of the embodiments of inserts described in U.S. patent application Ser. No. 13/270,072, titled “Method and Device for Delivering Medicine to Bone,” filed Oct. 10, 2011, and hereby incorporated by reference herein in its entirety. In use, the insert 912 is inserted into the second channel 902. A substance is then introduced into the proximal end 916 of the insert 912. The substance then exits the exit portal 914 of the insert and the exit portal 908 of the second channel 902 of the multichannel cannula 900. The insert 912 can be adjusted within second channel 902 to alter the amount of substance ultimately delivered through side exit portal 908 of the multichannel cannula 900. For example, the insert 912 may be pulled in a proximal direction (i.e., away from the multichannel cannula 900) such that only a portion of side exit portal 914 is aligned with side exit portal 908. Alternatively, the insert 912 can be pushed in a distal direction to fully align side exit portal 914 with side exit portal 908, as shown in FIG. 9, which maximizes the amount of the substance delivered through side exit portal 908. The insert 912 may also be rotated around its longitudinal axis to alter the alignment of side exit portal 914 of the insert 912 and side exit portal 908 of the multichannel cannula 900, thus adjusting the amount of the substance delivered. A delivery device 628 (shown schematically in FIG. 6), such as a syringe, a pump, or a reservoir, may be attached to the proximal end 916 of the insert 912.

In another exemplary method, any of the multichannel cannulas described herein may be used to remove material, such as bone marrow or blood, from the interior of a bone 10. Referring to FIG. 8, a suction device 826 may be coupled to the proximal end of multichannel cannula 800 to aid in the removal of material. In one embodiment, the suction device 826 is coupled to the proximal end of second channel 802 by tubing 829 or via a delivery portal (e.g., the delivery portal 604 shown in FIG. 6). Upon activating the suction device 826, material being removed from the bone 10 travels through the multichannel cannula 800 in an opposite manner from the embodiments in which a substance is being delivered to the bone through multichannel cannula 800. For example, in the embodiment shown in FIG. 8, activation of suction device 826 causes material to enter the multichannel cannula 800 through the exit portal created by open distal end 810 or through any side exit portals in the multichannel cannula 800. The material then travels through second channel 802 and exits the multichannel cannula 800 through the inlet portal 820 at the proximal end of the second channel 802. The exit portals of the multichannel cannula 800 may be aligned within bone 10 to remove material from intended locations near the exit portals.

A user may use the multichannel cannula 800 to both deliver substances to bone 10 and remove materials from the interior of a bone 10 during the same surgical procedure. In one embodiment, a user first uses the multichannel cannula 800 to remove material from the interior of the bone 10. Next, the multichannel cannula 800 is used to deliver substances to areas within the bone 10. Alternatively, a user may first deliver a substance to the interior of bone 10 using the multichannel cannula 800. After substance delivery, the user may remove excess substance (e.g., medication) or other materials (e.g., blood) by utilizing a suction device 826 coupled to the proximal end of the multichannel cannula 800. The combination of a multichannel cannula and an insert, such as the multichannel cannula 900 and insert 912 shown in FIG. 9, may similarly be used in connection with a suction device 826 to remove material from the interior of a bone 10. In this embodiment, the suction device 826 can be coupled via tubing or via a delivery portal (e.g., the delivery portal 604 shown in FIG. 6) to the proximal end 916 of the insert 912.

The multichannel cannulas described herein can be used to irrigate the interior of a bone by simultaneously delivering a substance to the bone 10 using one channel and applying a suction force to a separate channel. Irrigation may be useful for reducing the risk of infection or contamination within a bone. In one embodiment, a solution containing antibiotics or other medication is introduced into a first channel of a multichannel cannula. The solution travels through the first channel and enters the interior of a bone through one or more exit portals of the first channel. Simultaneously or shortly thereafter, a suction force is applied to a second channel of the multichannel cannula using a suction device, such as suction device 826 shown in FIG. 8. The suction draws the solution from the interior of the bone and back into the multichannel cannula through an open portal of the second channel. In this manner, the interior of the bone can be irrigated using a multichannel cannula. The channel used to deliver the substance to the bone may or may not contain a stabilizing wire 4. Similarly, the channel used to draw the substance back out of the bone may or may not contain a stabilizing wire 4. In other words, the presence of a stabilizing wire 4 within a channel does not prevent substances from flowing through the channel.

The various multichannel cannula embodiments can be used in surgical procedures other than in connection with delivering or removing substances from bone. For example, the multichannel cannulas can be used in procedures requiring insertion of a cannula into a vessel. In this embodiment, a guidewire is inserted into the patient's vessel, and a first channel of the multichannel cannula is then threaded over the guidewire. The cannula can then be used as described in connection with the various methods disclosed herein to deliver or remove a substance from the vessel through a channel of the cannula. In another embodiment, the multichannel cannula is used in ear, nose, and throat procedures, with or without the use of a guidewire.

The construction and arrangement of the devices and methods as shown in the various exemplary embodiments are illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, use of materials, orientations, etc.). For example, the position of elements may be reversed or otherwise varied and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of the present disclosure. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present disclosure. 

What is claimed is:
 1. A cannula for carrying a substance to and from a bone, comprising: a first channel having an open proximal end and an open distal end, wherein the first channel is configured to receive a stabilizing wire; a second channel having an inlet portal and an exit portal, wherein the inlet portal and the exit portal are in fluid communication; and a distal tip at a distal end of the cannula, the tip comprising a tapered portion and an engagement portion, and having a channel extending therethrough for receiving a portion of the stabilizing wire; wherein the engagement portion of the distal tip comprises a portion having a smaller diameter than an inner diameter of the second channel such that the engagement portion can be received within the second channel and wherein the engagement portion is coupled to the first channel; a cap closing at least a portion of the inlet portal and having a delivery port in fluid communication with the inlet portal of the second channel, the delivery port extending at an angle to a longitudinal axis of the cannula, and the cap further comprising a channel for receiving a portion of the cannula therein; and a plunger movable between a first position and a second position within the second channel, and wherein the cap is configured to fit over the cannula and a portion of the plunger.
 2. The cannula of claim 1, wherein the first channel and the second channel are coaxial.
 3. The cannula of claim 1, wherein the exit portal of the second channel is a side exit portal on an outer wall of the second channel.
 4. The cannula of claim 3, further comprising a plurality of exit portals on the outer wall of the second channel.
 5. The cannula of claim 1, wherein the exit portal of the second channel is a side exit portal on an outer wall of the first channel providing fluid communication between the second channel and the first channel.
 6. The cannula of claim 5, wherein the first channel further comprises a side exit portal on the outer wall of the first channel for delivery of the substance to the bone.
 7. The cannula of claim 1, further comprising the plunger having an inner lumen configured to fit around the first channel, and wherein the plunger is configured to be received between the first channel and the second channel.
 8. The cannula of claim 1, wherein the plunger has an inner lumen configured to fit around the first channel, and wherein the plunger is configured to be received between the first channel and the second channel, and wherein the channel receives a portion of the cannula and the plunger.
 9. The cannula of claim 1, wherein the cap comprises a flange extending outwardly at a distal side of the cap.
 10. The cannula of claim 1, wherein the delivery port is configured for attachment to a delivery device such that the delivery device is in fluid communication with the delivery port.
 11. The cannula of claim 1, further comprising an expandable portion disposed around a portion of the length of the cannula, wherein the expandable portion is configured to expand to form a contact between the cannula and the surrounding bone when inserted into an aperture in the bone. 